The present invention relates to a vial suited to deliver its contents without shards.
The delivery of topical medicine to the skin to treat skin conditions or to penetrate the skin for medicinal purposes is known. Likewise, the delivery of tooth whitener gel compositions is known. U.S. Pat. No. 7,201,577, for instance, discloses a tooth whitener applicator and method. The applicator is a conventional glass ampoule having a tooth whitening solution vacuum-sealed within a chamber of the ampoule. The whitening solution is a liquid based gel containing a whitening formula.
The conventional glass ampoule is contained within a cylindrical plastic sleeve closed at one end and enclosed at its other open end by the proximal termination of a brush-type applicator. An adhesive such as glue is used to adhere the periphery of the brush to the inner surfaces of the plastic cylinder. The bristles preferably have circular cross-sections so that when they are tightly packed together and adhered to the plastic cylinder, interstices between adjacent bristles are sufficiently large enough to permit flow through of the tooth whitening composition while being sufficiently small enough to prevent shards of glass from the ampoule, when popped or broken open, to pass through the brush. A cardboard sleeve surrounds the plastic cylinder to protect the user from the glass ampoule when broken.
The dimension of such interstices, therefore, imposes limitations on the tooth whitening composition. The presence of shards of glass affects the choice for design of the applicator, because it is necessary to prevent the shards from reaching the brush-type applicator for safety reasons. The solution proposed by U.S. Pat. No. 7,201,577 is to limit the size of the interstices. Such a solution, of course, would not be necessary if there were no shards.
Limiting the dimension of the interstices to prevent the passage of shards affects how viscous the tooth whitening composition can be. If the tooth whitening composition is too viscous, the interstices may become clogged due to the small size of the interstices to prevent the passage of shards through them. On the other hand, the more viscous the whitening composition, the better the whitening composition adheres to teeth, which is a desirable attribute for teeth whitening.
It would be desirable to eliminate the need to break a glass ampoule for delivering a tooth whitening composition gel. Indeed, it is desirable to prevent the creation of shards and thus (1) eliminate the need to take safety precautions to prevent the passage of the shards through interstices, (2) eliminate the need for a protective cardboard sleeve to protect the user from the shards, and (3) eliminate the risk of clogging of the gel at the interstices as might otherwise arise if the interstices size is too small and the viscosity of the gel is too high. By increasing the size of the interstices beyond that necessary to prevent the passage of shards, the viscosity of the gel may be likewise increased to enhance adhesion without creating the risk of clogging at the interstices.